Association Between Lactation and Postpartum Blood Pressure in Women with Preeclampsia.

PURPOSE: Preeclampsia affects 3% to 8% of all pregnancies. There are two distinct subtypes; early- (<34 weeks) and late-onset (≥34 weeks). Each subtype is associated with increased risk of cardiovascular disease. Lactation has been shown to improve cardiovascular outcomes. The purpose of this study was to describe lactation practices among women with each subtype of preeclampsia and determine the association between lactation and blood pressure at the initial postpartum visit. STUDY DESIGN AND METHODS: This retrospective cohort study included 246 subjects; 120 early- and 126 with late-onset preeclampsia who gave birth to live singleton newborns at a large suburban tertiary referral center in south central Pennsylvania between January 2012 and June 2016. Electronic health records were reviewed and data abstracted. Univariate and bivariate analyses were conducted. RESULTS: There was a significant difference in breastfeeding intent (p = .004) as well as rate of breastfeeding at maternal hospital discharge (p< .001) by preeclampsia subtype. However, there was no difference in rate of breastfeeding at the initial postpartum visit (p = .21) between subtypes. There was a significant difference in systolic (p = .03) and diastolic (p = .04) blood pressure between those breastfeeding and those who were not breastfeeding at the initial postpartum visit. CLINICAL IMPLICATIONS: Healthcare providers should provide women with preeclampsia clear and consistent messaging about importance of breastfeeding during pregnancy and the postpartum period on its association with improved neonatal outcomes, and specifically education on the cardioprotective benefit of sustained lactogenesis.

Comparative antigenicity and immunogenicity of hepadnavirus core proteins.

The hepatitis B virus core protein (HBcAg) is a uniquely immunogenic particulate antigen and as such has been used as a vaccine carrier platform. The use of other hepadnavirus core proteins as vaccine carriers has not been explored. To determine whether the rodent hepadnavirus core proteins derived from the woodchuck (WHcAg), ground squirrel (GScAg), and arctic squirrel (AScAg) viruses possess immunogen characteristics similar to those of HBcAg, comparative antigenicity and immunogenicity studies were performed. The results indicate that (i) the rodent core proteins are equal in immunogenicity to or more immunogenic than HBcAg at the B-cell and T-cell levels; (ii) major histocompatibility complex (MHC) genes influence the immune response to the rodent core proteins (however, nonresponder haplotypes were not identified); (iii) WHcAg can behave as a T-cell-independent antigen in athymic mice; (iv) the rodent core proteins are not significantly cross-reactive with the HBcAg at the antibody level (however, the nonparticulate "eAgs" do appear to be cross-reactive); (v) the rodent core proteins are only partially cross-reactive with HBcAg at the CD4+ T-cell level, depending on MHC haplotype; and (vi) the rodent core proteins are competent to function as vaccine carrier platforms for heterologous, B-cell epitopes. These results have implications for the selection of an optimal hepadnavirus core protein for vaccine design, especially in view of the "preexisting" immunity problem that is inherent in the use of HBcAg for human vaccine development.

Combinatorial approach to hepadnavirus-like particle vaccine design.

The particulate hepatitis core protein (HBcAg) represents an efficient carrier platform with many of the characteristics uniquely required for the delivery of weak immunogens to the immune system. Although the HBcAg is highly immunogenic, the existing HBcAg-based platform technology has a number of theoretical and practical limitations, most notably the "preexisting immunity" and "assembly" problems. To address the assembly problem, we have developed the core protein from the woodchuck hepadnavirus (WHcAg) as a new particulate carrier platform system. WHcAg appears to tolerate insertions of foreign epitopes at a greater number of positions than HBcAg. For example, both within the external loop region and outside the loop region a total of 17 insertion sites were identified on WHcAg. Importantly, the identification of an expanded number of insertion sites was dependent on additional modifications to the C terminus that appear to stabilize the various internal insertions. Indeed, 21 separate C-terminal modifications have been generated that can be used in combination with the 17 insertion sites to ensure efficient hybrid WHcAg particle assembly. This combinatorial technology is also dependent on the sequence of the heterologous insert. Therefore, the three variables of insert position, C terminus, and epitope sequence are relevant in the design of hybrid WHcAg particles for vaccine purposes.